After Fukushima Daiichi Nuclear Power Plant Accident in 2011, a new device called “Beta Panel Σ” was released that can test for body surface contamination in designated areas. It can measure head, face, back of hands, palm of hands and shoe sole.

Since this device has not yet been widely used nationwide and has not been evaluated by users, we conducted a basic performance evaluation this time. As a matter of consideration, we investigated whether the measured values would be similar using background and radiation sources. As a result, it was found that there were no problems in using it, but it was also found that there were some points that needed to be taken care of.

Items to be included in the radiation worker certificate were discussed based on Act on the Regulation of Radioisotopes, etc. and the Regulation on Prevention of Ionizing Radiation Hazards. The study was divided into cases in which the certificates should be submitted from an employer to an organization with a controlled area and cases in which the employer changes the organization due to a job change, etc., and radiation exposure control, education and training, and medical surveillance, respectively. As a result, it was concluded that in the former case, items related to education and training according to the radiation hazards prevention program of the facility to which the certificate should be submitted and items required for medical surveillance should include the date, the name of the physician, and the results. In the latter case, it was concluded that effective dose and equivalent dose to lens of the eyes for up to 5 years, education and training in accordance with the radiation hazards prevention program of the facility to which the certificate should be submitted, and the date, name of the physician, and results before entering the controlled area and the latest medical surveillance were required.

Radioisotope Laboratory at Tohoku University, built in 1973, has been used for various nuclear research involving unsealed and sealed radioisotopes, as well as nuclear fuel materials. Since the facility was deteriorated after over 50 years of use, a major renovation of the facility was undertaken in 2024. The renovation aimed to create a sustainable facility that is user-friendly for researchers, easy to manage for staff, and environmentally responsible. Key updates included replacing the under-ground effluent storage tanks with upper-ground ones, as well as updating the major equipment such as the drainage, exhaust and electrical system. This paper presents a case study report on the renovated facility and the series of processes involved in the renovation of a radioisotope facility.

Radiation accidents are reported to the International Atomic Energy Agency. Using the LAKA Foundation database, knowledge regarding radiation accidents at overseas radiation facilities from 2021 to 2024 was collected and examined whether there were any similarities with the previous report or not. The importance of fostering a safety culture, creating procedure manuals and the education & training was reaffirmed. There were reports from a new perspective. Succession of accident response, responsibility of employer, and the management of X-ray generator are a new concern. The trends in INES evaluation reports were examined from the beginning to 2024. It was also investigated whether there were any differences among countries. There was a good example of how to respond when accident occurred. The use of INES evaluation reports was also proposed for cultivating radiation management.

The range in water of low-energy β-particles emitted from radioisotopes such as tritium is same scale as the size of a cell. Thus, the energy transferred to a cell varies depending on the distribution of radioisotopes inside and outside the cell. In this study, a model of a cell culture system was created to estimate the energy transferred to cultured cells. Conventional calculation methods consider the energy transferred to the entire culture medium to be equal to the energy transferred to the cells therein, whereas the present method takes into account the distribution of radioisotopes inside and outside the cells. This showed that the absorbed dose to cells changes significantly depending on whether radioisotopes are taken up into the cultured cells.